While making a website, it is vital to make a website that is safe for both users and website owner. Everybody is aware of spammers flooding the internet. They misuse the website and keep posting spam comments. As a developer or designer it is vital for you to understand what is a Captcha, why are they used and where. So, In this article, we are shedding some light on What is Captcha, Why they are used, Where are they used and also a list of Top 11 WordPress Captcha Plugins.